I've visited foreign countries and within a few days, you just naturally start picking up the language. These new "immigrants" are NOT interested in anything about this country except what they can bleed from it. If they'd turn off their "special " language TV and just watch regular English TV, they'd be able to get by in a few weeks with English. They don't WANT to and they don't HAVE to. That's why they hang on to their cultural language, nation building..."a nation within a nation", as they say.
Exactly. And many of them hate us.